Grounding Basics
Everyone involved with electrical system safety or lightning protection needs to thoroughly understand the importance of electrical grounding. Even though the concept of grounding has been well known for more than a century, in too many cases grounding is poorly understood and implemented.
So, let’s go over the basics.
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“Ground” is the surface of the Earth existing as soil or rock of various compositions.
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The term “grounding” (also more globally referred to as “earthing”) refers to the method of creating an optimum path for electricity to reach the earth safely.
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“Soil resistivity” is a measurement of the resistance of earth materials (soils and rock) to the movement of electrons (electric current). “Current” can exist as the return flow of commercially generated electricity, as static electricity, as lightning, or even as an electromagnetic pulse.
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Depending upon geography, moisture content, soil composition, and geology, the conductivity of the Earth can vary greatly.
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Soil resistivity levels are absolutely critical to the performance of grounding/earthing systems. Lowering the resistivity of the soils immediately adjacent to grounding/earthing devices helps ensure fault currents from any source are directed to, and efficiently dissipated into, the Earth.
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Fault current dissipation is substantially impacted by what is often a very large impedance mismatch between a traditional grounding system and native soil. Creating an “impedance gradient” between the entry point of the fault current to the grounding system and native soil dramatically improves system performance.
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In the case of high-intensity fault currents, properly managing the very large range of frequencies that can accompany such faults (especially lightning) is essential to the effectiveness of a grounding system
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Highly or even moderately resistive (to current flow) soils cause surprising increases in resistance-to-ground. This condition is exacerbated by impedance mismatches and frequency content issues. The performance of traditional grounding systems, which ultimately rely nearly exclusively on collections of simple copper-clad or galvanized steel ground rods, is dramatically impacted by variations in soil resistivity, as well as an inability to manage broadband / high frequencies.
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Hence, understanding how conductive or resistive soils are – and therefore the degree of the inherent impedance mismatch between system and soil, along with how well a system will dissipate the full range of fault frequencies, are essential in designing and maintaining effective, safe grounding systems.
Grounding 101
All electricity, including lightning, performs in terms of flow, in rather predictable ways – governed by natural law. Electricity always seeks the pathway of lowest resistance as its primary route to ground, and will traverse, often destructively, any impediment in its path to get to its destination.
However, if the least resistant path to ground for any fault current is carefully mapped and engineered to bypass critical assets and people, this flow of electricity can be safely dispersed. It is the "business end" of the path, where the final rendering of the current harmless occurs, that GroundLinx Technologies was created to address.
Traditional Methods
versus
The GroundLinx Gradiance™ System
Grounding of electrical devices and installations is universally known to be critical to the performance and safety of these assets. In fact, according to the IEEE, a white paper presented recently at the Petroleum and Chemical Industry Technical Conference, “The history of using the earth as an electrical conductor for man-made electricity for the past 270 years is detailed in this paper.” That means we’ve been “onto” grounding for nearly three centuries.
In spite of this, traditional grounding methods typically employed over the last 100 years or so – while compliant with code standards – have rarely, if at all, taken soil resistivity and fault frequency content attributes fully into account.
Over the last fifty years, asset losses due to insufficient or incorrect grounding have multiplied at extraordinary rates, due largely to the expansion of use of very sensitive (and often very expensive) electronic devices in virtually all aspects of our lives. Unmanaged fault currents, from surges and spikes to lightning strikes, can easily destroy these sensitive devices….or structures and systems.
In an attempt to compensate for these deficiencies, design engineers routinely specify connection of dozens of ground rods, often driven 50 feet (15 meters) or more into the Earth to create an extensive, costly array of emitting points for fault current over a very large land footprint. Surprisingly, the formulae used to derive these designs often massively underestimate the impact of resistive soil on dissipation of current by a ground rod. Additionally, impedance mismatching and high frequencies in the introduced fault current are not addressed. In these conditions, the vast majority of current dispersal from a ground rod occurs at its buried tip, not along its buried length. The reasoning is simple: Copper is a great conductor, with very little resistance. High resistivity soils (and rock) are not. Electrons will “prefer” to flow through the copper cladding of the ground rod instead of dissipating in the adjoining poor-conductivity soil, until they are forced off at the tip. With egress from the rod severely constrained, undesirably high system resistance becomes a severe impediment to dissipation of current, especially in a high frequency “steep wave front” event, such as lightning.
A traditional 19th Century lightning rod
Too often, the bottom line is failure of the grounding system: Current unable to reach ground instantaneously seeks all other possible outlets for dissipation - as current and heat - through equipment and structures which were supposed to be protected. Catastrophic losses can easily result.
Ground rods, and their supporting connection strategies, work quite well in high conductivity soils. But, in the absence of these ideal conditions (amazingly common around the world), traditional rod, grid, and plate-based systems – which are at the heart of nearly every grounding/earthing and lightning protection system available – are not as effective or stable as is necessary for proper safeguarding of critical systems and structures.
The traditional solution is basically a “the more metal, the better” approach, thereby overcompensating for soil unknowns and variability.
The real solution is first, to test and fully understand soil resistivity at a location, and second, to deploy a highly resilient, broadband-capable system that economically and reliably functions in observed resistivity conditions, and varying soil moisture levels, regardless of the characteristics of the fault input.
GroundLinx Technologies has re-thought, re-imagined, and re-invented electrical grounding.
The GroundLinx Method
A Revolution in Electrical Grounding
When we set out to create a robust solution for grounding in less-than-ideal conditions, we quickly focused our efforts on dramatically expanding the number of emitting points for current carried by any electrode in any soil condition, all in a compact size, with a manageable land footprint and installation depth.
Combining unique-to-this-use proprietary components in a novel and innovative way allows us to dramatically increase and maintain the conductivity of soil surrounding a grounding electrode by:
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Creating a perimeter of very conductive “ground” that vastly exceeds the circumference and surface area of the classic ground rod,
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Making the entire length of the buried electrode capable of current dissipation, not just the tip, even in poor soils.Contrary to present teaching, due to impedance mismatches, ground rods emit very little current along their length. The vast majority is emitted at the tip of the rod, and
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Coupling all elements of the system with highly durable materials that have literally millions of “jumping off points” for any fault current entering the system.
Dissipation is further enhanced by a sequential use of proprietary materials that create the aforementioned impedance gradient
for current to easily follow from entry point to native soil. This current is broadly dispersed into surrounding soils, dramatically reducing system resistance-to-ground generally by 55-85% versus traditional grounding methods. (In certain "extreme-conditions" installations, reductions of 98% have been achieved.)
Application of simple principles of physics and advanced application of materials science to the GroundLinx Gradiance™ systems has resulted in the first truly structural improvement in grounding technology in over three decades.
GroundLinx is revolutionizing the science of grounding.
